Method for controlling yarn



Dec. 5, 1950 E. ST. PIERRE METHOD FOR CONTROLLING YARN Filed Dec. 11,1947 FIG. 3.

{NI 11705: GENEJZHERRE;

Patented Dec. 5, 1950 METHOD FOR CONTROLLING YARN Eugene Hemphill St.Pierre, Pawtucket, R. 1., assignor to Company, Central Falls, R. 1., acorporation of Massachusetts Application December 11, 1947, Serial No.791,051

1 Claim. 1

This invention relates to a new and useful improvement in a method anddevice for controlling yarn in sources to the device by which it is usedsuch as the needles of a knitting machine. It was devised for use with acircular, independent needle, hosiery knitting machine of the Bannertype and the description will be based upon such a use. However, it isequally useful with other types of knitting machines and also withwinding and other machines where the same problem is encountered.Certain yarns, particularly nylon, present special problems to theknitter. One is its tendency to untwist which apparently Originates inthe general vicinity of the needles and extends back through the guidesand tensions to the cone. When knitting is discontinued, the yarnunwinds a little from the cone creating slack. When this occurs, theyarn tends to twist upon itself to form outstanding pigtails which whenknitting is resumed may straighten out or concentrate into knots. Brokenyarn, defective fabric, broken needles and other difficulties resultfrom such knotting. It is a characteristic which has caused greatannoyance to users of certain yarns of which nylon is a conspicuousexample and which, as far as is known, has been eliminated only by thisinvention.

One form of the invention is shown in the drawing of which:

Fig. 1 is a side elevation of such parts of a Banner knitting machine asare required for an understanding of the invention;

Fig. 2 is a rear elevation of the same parts;

Fig. 3 is a view illustrating the characteristic kinking of nylon whichthis invention prevents;

Fig. 4 shows a modified form of the invention; and

Fig. 5 shows a second modification.

As is well known, a knitting machine is provided with one or moresources of yarn, generally a cone, from which the yarn is run throughsuitable guides and tensions to the yarn levers and needles. As shown inFig. 3, yarn I, assumed to be nylon, originates at the cone 2 and passesthrough eyelet 3 and, generally, additional eyelets, not shown, as wellas one or more tensioning devices on its way to the yarn levers andneedles.

While knitting is going on, the yarn runs continuously from the cone andis under some tension throughout its length so that no difiiculties withits travel are encountered. However, when knitting is stopped, a certainamount of slack appears adjacent the cone and may extend to the far sideof one or more of the yarn guides whereits passage from its cone or fromother upon the yarn is almost certain to twist upon itself into pigtailssuch as those shown at 4 and 5 in Fig. 3 which may or may not disappearwhen knitting is resumed. If they do not, knitting and mechanicaltroubles are certain to result.

The cause of this pigtailing of the yarn appears to be the untwisting ofthe yarn itself beginning adjacent the needle end of its travel which isreflected all the way back to the cone. When slack appears anywhere,pigtailing is likely to occur particularly if the length of yarn betweenadjacent guides or a guide and the cone is of any great length. At timesit is practically impossible to knit nylon yarn for this reason unlessthe machine is kept in continuous operation.

This difiiculty has been completely solved by the simple but whollyeffective method and device of this invention. The form shown in Fig. 1consists essentially of a small spool or pulley 6 adapted to rotate withgreat freedom upon a pin 1 aflixed to a bracket 8 which is mounted upona suitable part, such as the spider 9, of the machine more or lessmidway of the travel of the yarn between the cone and the needles. Theyarn I after passing through on or more guides such as I0 and II isgiven a turn around pulley 6 and is then led to the needles through theusual guides and tensions. While knittin is going on, pulley 6 is causedto rotate by the pull upon the yarn produced by the needles. Whenknitting is stopped, the pulley stops. Any tendency to overrun may beprevented by a tension l 2 on the cone side of the pulley. This tensionmay serve as the or one of the regular tensions by which the knitting isregulated.

The pigtailing of the yarn heretofore described and which has been sucha serious problem is wholly eliminated by pulley 6 used in this way. Inefiect, the start of an artificial pigtail is produced by the loop ofyarn around pulley 6 which is prevented from twisting upon itself toform a pigtail by the pulley. Also the bending of the yarn around thepulley stops its internal untwisting. Consequently, the yarn remainingbetween the pulley and the cone is effectively insulated from the causeswhich would normally produce pigtailing since these lie on the otherside of pulley 6 and cannot proceed beyond that pulley. As a result,nylon and other difficult yarns can be used as easily as any of the manyother yarns with which this troublesome characteristic is notencountered.

In Fig. 4 a modification is shown in which the yarn is given a partialturn instead of a full turn around a pulley I3 which corresponds topulley 6. In this instance, it will be noted that the yarn reverses itsdirection so that the suggestion of a loop, such as that shown at 4 inFig. 3 which is characteristic of pigtailing, is clearly suggested. Tobe effective, the yarn should be in contact with the pulley for aconsiderable length of its circumference. Otherwise, the effectivenessof the device is progressively impaired; In other words, the yarn aboutthe pulley must have what is definitely recognizable as th beginning ofa complete loop as distinguished from mere bandbut the exact minimumrequirementldepends up-- on so many features that it can be determinedonly by trial.

In the form of the invention illustrated by Fig;

5, it will be noted that there are two pulleys M and I 5, eachcorresponding, to pulley-wand that the yarn is passed around one side ofone pulley and around the other side of the other pulley. While thedirections of the ends of the yarn are divergent, the suggestion .of adefinite. loop, such as that shown in Fig. 4 is preserved; In thiszinestance, there are two such loops: In both the modified forms, as in theoriginal form, thepulley or pulleys act as before withtheIBSlllUtl'lEilplg tailing tendency is eliminated.fromrthefiremainingyarn.

If greater resistance to the: travel. ofF-theyarn is not objectionablea. pin or othernon-rot'ating element may replace the pulley and, ofcourse, the term pulley includes anyform of ifreely r;- tating element,

In the following claim the-words-l'oop and looped are'te be understoodto include not-only the complete loop described-in co-nnectionwiththe'form of the invention of'F-ig; 1-butalso partial loops or incompleteloops, such as those shown in Figs. 4 and 5 or, in other words; any loop-or bend in the yarn around an element which is suflicient to eliminatethe pigtailing -tendency;de-

scribed. The degree of bend or loop in the yarn required for the purposeof this invention will vary with the kind, size and twist of the yarnand the mechanical arrangement of the machine and, consequently, cannotbe more exactly specified.

I claim:

Amethod of controlling a length oftwisted nylon yarn running fromasource of supply to a point where it is used progressively, such as toa'knitting needle, under conditions causing an alteration in thetwist ofsaid yarn and a consequent tendency to pigtail if slack occurs adjacentsaid source of supply, which includes the steps of drawing saidyarn fromthe source of supply under no tension other than that resulting from thewithdrawing of. said yarn to a tensioning device and thereafter forminga loop in said yarn and maintaining said loop in a single plane toprohibit transmission of alterations in yarn twist andeonsequentitendenoy to pigtailin the length of yarn between said sourceoffsupply'an-dv said tensioning device.

EUGENE ST. PIERRE...

REFERENCES CITED The following references are of recordin the file ofthis patent:

UNITED STATES PATENTS Number Name Date- 1,977,686' Mayer Oct: 23, 19342,158,547 Lawson et a1 May 16,1939 2,432,518 Eshleman Dec: 16, .1947

FOREIGN PATENTS Number Country; Date 531,438 France Jan.v 12, 1922568,259 Germany Jan. 17, 1933 686,055 Germany Jan.2, 1940

